The present invention relates to automatic packaging of various products, in particular tablets, pills, capsules and the like, in blister packs.
In particular, the present invention relates to a station including a device for feeding products which are placed in the blisters of a band running under the device.
Blister packs have been used so far especially for packaging pharmaceutical products. Blister packs are formed by a plate provided with a plurality of receptacles, called blisters, which contain products.
This plate is usually sealed with a sheet of e.g. aluminum and the products are then removed by the user by tearing or ripping this sheet.
The blister packs are obtained by a sequence of operations, usually as follows:
forming, in a special forming station, of one or more lines of blisters in a continuous band of a suitable material, usually heat-formable plastic or a laminate. A laminate is formed by more layers of material, one of which is aluminum;
subsequent passage of the so obtained blister band through a filling station, where at least one product is introduced into each blister;
definite sealing of the surface where the blisters are open by applying and welding a film of e.g. aluminum.
The so obtained, filled blister band is then cut into sections containing a predetermined number of blisters, and consequently, of products, thus defining the blister packs.
Other known apparatuses fill the blisters with products according to other techniques.
One of these apparatuses includes a box-like container without bottom, which is situated directly over the blister band and whose width is not bigger than the width of the blister band.
The band is moved forward with the blisters openings turned towards the inside of the container, so that they pass, one after another therebelow.
The container is fed by a feeding channel which conveys such a number of products to be fed to the blisters, so that they accumulate on the band surface.
Sorting means using brushes and the like, and other distributing means, spread the accumulated products so that they enter empty blisters and translate with the band until they leave the container.
The exceeding products remain inside the container.
The above described system can be used with bands moving in a continuous or intermittent way and does not require the alignment of the products with respect to the corresponding blisters.
However, there is a series of problems connected with the filling technique.
First of all, the products, specially very fragile ones, can be scratched or chipped due to repeated mutual pushes and rubbing against the band surface as well as against the container walls.
Moreover, if the blisters diameter is bigger than the products diameter, each blister can receive more products.
According to another used system for blisters filling, the products are piled in a plurality of channels, each of which is situated right over a line of blisters made along the band.
The lower part of the channels opens onto the band surface and, in time relation with the band movement, the products fall, due to gravity force, into the blisters as they pass below the channel.
The channels are connected in parallel with a basin-like, vibrating feeding device, in which the products are contained in bulk.
The basin vibrations facilitate regular introduction of the products into each channel.
However, the same vibrations damage the products, produce dust and noise.
If the dust is dangerous for the operators, the whole apparatus is closed in a space isolated from outside and connected with appropriate dust collectors.
The present invention has been evolved with a general object of proposing a device for filling a blister band with products, in particular tablets, pills, and capsules, which device fills each blister with only one product, avoiding damages of products as well as of the blister band, independently from the shape and dimensions of both.
Another important object of the present invention is to propose a device for feeding products, called hereinafter also feeding device, with which the products are not subjected to vibrations, which does not produce dust and which reduces the noise caused by the products being fed to the blister band.
A further important object of the present invention is to propose a device for feeding products, which is highly reliable and productive in any conditions without changing the functionality of the whole packaging machine.
Still another object of the present invention is to propose a device, which uses blister bands made of any material, thus allowing them to be fed with products of different shapes or composition, and allowing particularly rapid and easy the adjustments necessary for adapting the system in relation to the packaging cycle characteristics.
Yet a further object of the present invention is to propose a device for feeding products, which can be used with any blister packaging machine, and which is obtained by a simple, cheap, extremely functional and reliable technical solution.
Another object of the invention is to design a device having reduced dimensions.
The proposed device must also guarantee a correct packaging phase relation when the products are packed into the corresponding blister bands.
The above mentioned objects are obtained, in accordance with the contents of the claims, by a device for filling a blister band with products, with the blister band having at least one longitudinal line of blisters for receiving the products and driven in a forward direction, the device including:
a hopper, the products being stored in bulk within said hopper, with said hopper being delimited by walls and having an open bottom;
taking over means, located at said open bottom of said hopper and acting on said products, so as to slightly push said products upwards, with said taking over means defining at least one opening, with one product at a time passing, suitably oriented, through said opening;
conveying means defining at least one channel having an inlet situated directly under said opening and an outlet;
delivering means, connected to said channel and aimed at transferring products from said conveying means to the blisters of said blister band.
The taking over means include one roller, situated beside one wall of the hopper and rotating upwards in a region where the roller touches said hopper wall, with said roller forming, on its outer surface, at least one circumferential groove, said groove defining, together with said hopper wall, said opening in said region where the roller touches said hopper wall.